In electric appliances having temperature measuring, such as for example the aforementioned cooking appliances, the temperature measuring can be very relevant in terms of security, in particular in the case of the aforementioned fryers. Temperature sensors are intended to prevent an excessive temperature, which presents an accident hazard. In that context, temperature sensors can have malfunctions, for example due to manufacturing errors in the measuring resistor, due to aging or other types of damage.
It is known from U.S. Pat. No. 5,713,668 that, so to say, a temperature sensor prefers self-testing in the temperature measuring device and that two thermocouples and one resistance sensor are provided for this purpose.
Further temperature measuring devices are known from DE 10 2004 035 014 A1 and DE 20 2009 003 889 U1.